Power assist for a manual and autoinjector injection device

Abstract

A power-assisted injection device can administer a liquid medication. The injection device can include a syringe, a housing, and a motive force device. The syringe can include a plunger and a barrel configured for holding the liquid medication. The housing can include a body configured for holding the syringe. The housing can also include a latch configured to define a locked position that inhibits movement of the plunger and a released position that enables movement of the plunger. The motive force device can be configured for applying an injection force to the plunger to administer the medication while the latch is in the released position. The injection device can be configured for administering the liquid medication upon release of the latch from the locked position at least in part via the motive force device applying the injection force to the plunger of the syringe.

1 . A power-assisted injection device for administering a liquid medication, the injection device comprising:
 a syringe including a plunger and a barrel adapted for holding the liquid medication;   a housing including a body adapted for holding the syringe and a latch configured to define a locked position that inhibits movement of the plunger and a released position that enables movement of the plunger, the housing including a first end and a second end opposite the first end along a central axis, the plunger configured to move in a first direction toward the second end to administer the medication;   a syringe holder configured to couple to the barrel;   a needle guard configured to move axially relative to the syringe holder to transition between an initial position in which the distal end of the discharge port extends out of the needle guard, and a retracted position in which the distal end of the discharge port is retracted into the needle guard; and   a motive force device coupled to the second end of the housing, the motive force device configured for applying an injection force to the plunger to administer the medication while the latch is in the released position;   whereby the injection device is configured for administering the liquid medication upon release of the latch from the locked position at least in part via the motive force device applying the injection force to the plunger of the syringe.   
     
     
         2 . The injection device of  claim 1  wherein the motive force device is at least one spring engaged with the body of the housing. 
     
     
         3 . The injection device of  claim 2  wherein the housing includes a flange configured to translate relative to the housing body and configured to contact the plunger to apply the injection force to the syringe. 
     
     
         4 . The injection device of  claim 3  wherein the housing includes a base proximate an upper portion of the barrel of the syringe, the at least one spring of the motive force device is a pair of springs in tension between the housing base and the housing flange. 
     
     
         5 . The injection device of claim of  claim 4  wherein the latch is a protrusion within the housing, the protrusion contacting an underside of the housing flange when the latch is in the locked position, thereby retaining the housing flange in the locked position until release. 
     
     
         6 . The injection device of  claim 1 , wherein the motive force device is a spring that is coaxial with the plunger. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . The injection device of  claim 1  wherein the motive force device is a pair of magnetic components, each one of the magnetic components being a magnet and/or a ferrous structure, whereby attraction between the pair of magnetic components applies the injection force to the plunger. 
     
     
         13 . The injection device of  claim 12  wherein a first one of the pair of magnetic components is fixed relative to the housing proximate a barrel of the syringe and second one of the pair of the magnetic components is coupled to the plunger at or near a plunger flange. 
     
     
         14 . The injection device of  claim 13  wherein the first one of the pair of magnetic components is a first magnet and the second one of the pair of magnetic components is a second magnet oriented to attract the first magnet. 
     
     
         15 . The injection device of  claim 13  where the magnets are spaced apart until the completion of the administration of the medication. 
     
     
         16 . A power-assisted injection device for administering a liquid medication, the injection device comprising:
 a syringe including a plunger and a barrel adapted for holding the liquid medication;   a housing including a body adapted for holding the syringe and a latch configured to define a locked position that inhibits movement of the plunger and a released position that enables movement of the plunger; and   a motive force device configured for applying an injection force to the plunger to administer the medication while the latch is in the released position;   whereby the injection device is configured for administering the liquid medication upon release of the latch from the locked position at least in part via the motive force device applying the injection force to the plunger of the syringe,   wherein the motive force device is a first spring and a second spring, the first spring and the second spring being configured for actuation at least partly in series.   
     
     
         17 . The injection device of  claim 16  wherein the housing includes a divider separating the first spring from the second spring, the divider configured for movement relative to the housing body. 
     
     
         18 . The injection device of  claim 17  wherein the latch is a first and second latch, wherein release of the first latch engages actuation of the first spring and release of the second latch engages actuation of the second spring. 
     
     
         19 . The injection device of  claim 18  wherein the housing further includes an inner frame configured for engage the plunger, the inner frame being moveable relative to the housing body and the divider, wherein upon release of the first latch and before release of the second latch, the first spring moves from a compressed position to an extended position, and upon release of the second latch the second spring moves from a compressed position to an extended position. 
     
     
         20 . The injection device of  claim 3 , wherein the translatable housing flange includes a contact portion configured for contact by a user to move the housing flange upwardly to reset the motive force device. 
     
     
         21 . A power-assisted injection device for administering a liquid medication, the injection device comprising:
 a syringe including a plunger and a barrel that is configured for holding the liquid medication;   at least one spring configured for applying an injection force to the plunger to administer the medication;   a housing including a body configured for holding the syringe and a flange configured to translate relative to the housing body and configured to contact the plunger to apply the injection force to the syringe; and   a load actuator configured for loading the spring;   whereby the injection device is configured for administering the liquid medication upon loading of the spring.   
     
     
         22 . The injection device of  claim 21  wherein the load actuator includes a linkage assembly configured to move the at least one spring from a fired position to a ready position. 
     
     
         23 . The injection device of  claim 22  wherein the linkage assembly includes a lever arm assembly including a lever arm and a pivot fixed on the body of the housing. 
     
     
         24 . The injection device of  claim 23  wherein the linkage assembly further includes at least one linkage arm pivotally coupled to an interior end of the lever arm, whereby applying a force to the lever arm transmits a loading force through the linkage arm upward to compress the at least one spring. 
     
     
         25 . The injection device of  claim 23  wherein (i) the linkage assembly further includes a linkage arm pivotally coupled to an interior end of the lever arm, (ii) the at least one spring is a pair of springs engaged with opposing ends of the housing flange, and (iii) the at least one linkage arm is a pair of linkage arms engaged with opposing ends of the housing flange, whereby applying a force to the lever arm transmits a loading force through the linkage arms upward to compress the springs. 
     
     
         26 . The injection device of  claim 22  wherein spring is a coaxial spring that disposed about the plunger. 
     
     
         27 - 44 . (canceled)